多对一关联转换为职位 [英] Many to one association converting to postres

问题描述

我正在将Rails应用程序从sqlite转换为postgres，以便可以与heroku一起部署。我已经安装了postgres并进行了迁移，但是当我尝试运行查询以查找与房屋相关的所有室友时，出现以下错误

I am in the process of converting a rails app form sqlite to postgres so that I can deploy with heroku. I have postgres installed and I ran migrations, however when I try to run a query to find all the housemates associated with a house I get the following error

PG::Error: ERROR:  operator does not exist: character varying = integer
LINE 1: SELECT COUNT(*) FROM "mates"  WHERE "mates"."house_id" = 1
                                                           ^
HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
: SELECT COUNT(*) FROM "mates"  WHERE "mates"."house_id" = 1

此错误源自注册视图，您在添加房屋后将其重定向到创建视图并成为管理员。这是视图代码：

This error originates form a sign-up view that you are redirected to to create and administrator after adding a house. Here is the view code:

Extracted source (around line #4):

1: <div class="container">
2:  <div class="row">
3:      <div class="span5 offset3">
4:          <% if current_house.mates.empty? %>
5:              <h2>Add an Administrator</h2>
6:          <% else %>
7:              <h2>Add a New Housemate</h2>

感谢所有帮助！

推荐答案

转到 add_house_id_to_mates 迁移并将第3行从字符串更改为整数。
之后，删除 20130628212206_change_type_of_house_id_in_house.rb 迁移。

Go to add_house_id_to_mates migration and change line 3 from string to integer. After this, remove the 20130628212206_change_type_of_house_id_in_house.rb migration.

从零开始运行迁移：

rake db：drop db：create db：migrate

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